Cutting One's Nails

From Halachipedia

Disposing of one's nail clippings

  1. When one cuts (or bites) one's nails, one must make sure that none of the clippings remain on the floor. It’s best to burn one's nail clippings. The next best option is to bury them. [1] Some poskim allow flushing one's nails down the toilet or washing them down the sink if one leaves the water running for a few minutes. [2]

References

  1. Mishna Brurah 260:6 quoting the gemara Moed Katan 18a. The Gemara Moed Katan 18a writes that if a pregnant woman steps on nail clippings there is a danger that she might loose the child she is carrying. The gemara continues that when one cuts (or bites) one's nails, one must make sure that none of the clippings remain on the floor. It’s best to burn one's nail clippings. The next best option is to bury them. This is brought as halacha by the Mishna Brurah 260:6 and Amot Shel Halacha (by Rabbi Ari Enkin). Rabbi Enkin quoting the Bear Hetiev 260:2 writes that the reason for this is that before the sin of the forbidden fruit, Adam and Eve wore garments made of a fingernail-type substance. After they sinned God took away this Divinely provided clothing. Since it was Eve who was essentially responsible for this loss, our fingernails – which recall these clothes – are said to bring harm to pregnant women. Of course, this is a spiritual and not a scientific matter.
  2. Halachically Speaking (vol 4, issue 22) quoting Rav Yisrael Belsky allows flushing one's nails down the sink. Halachically Speaking also extends this to washing the nails down the sink if one leaves the water running for a few minutes. Rabbi Mansour also assumes that this would be acceptable.